Engine tapping sound

2008 CHEVROLET TRAILBLAZER
30,000 MILES • 6.0L • V8 • AWD • AUTOMATIC
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DRE68
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Engine starts to make a tapping sound when warmed up. the sound is slight at idle but when accelerating or increasing rpm it is more pronounced. oil pressure is fine ,no check engine lights or noticeable loss of power. does not make a knocking sound like when I spin a rod hearing. you cannot hear it during start-up. only at normal operational temperature. appreciate your time and opinion..
Jun 4, 2017 at 8:13 PM
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STRAILER
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Hello,

It sounds like the oil is broken down and needs to be changed. Use Mobil1 for this change to see if that helps, here is a guide to help you get the problem fixed.

https://www.2carpros.com/articles/how-to-change-engine-oil-and-filter

Please let us know what happens.

Cheers, Ken

Jun 7, 2017 at 8:59 AM
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DRE68
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I change oil every 3,000 miles with Mobil 1...tapping sound continued after engine reached 210 after recent oil change...the sound comes once the engine reaches temp...
Jun 7, 2017 at 10:19 AM
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HMAC300
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you really need to explain more if you can like is it top engine or more towards bottom may be cam/rocker wear or maybe piston slap.
Jun 7, 2017 at 12:16 PM
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DRE68
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Engine was rebuilt 5/2016...due to ingesting water & breaking a rod....ran fine until April of this year when the tapping started....the sound seems to be coming from the top passengers side...loud tapping after warm-up...never when started or cold...
Jun 7, 2017 at 12:40 PM
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HMAC300
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then pull that valve cover off and check for loose rocker arms like it may have bent a pushrod or lifter leakdown something like that.Or even a broken valve spring but I kind of doubt that as it would more than likely misfire.
Jun 7, 2017 at 3:19 PM
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